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To fulfil the hunger for sustainable development, Australian construction sector seems to contemplate toward green design. Green-Star environmental rating system, one of the active building rating systems in Australia, has also been employed in New Zealand, and South Africa. To help engineers and designers obtain comprehensive visualisation on sustainable projects, this paper develops a model to evaluate energy consumption and greenhouse-gas emissions based on typical Australian commercial building alternatives. From that, this paper explains how to achieve points for “Energy” and “Life-cycle impacts” categories of this rating system. The model uses GaBi 8.1 platforms and shows relationships between building's energy consumption, and greenhouse-gas emissions released during the building lifetime. This paper provides insight into life-cycle greenhouse-gas emissions assessment for several typical commercial building fabrics in Australia. The developed model can also be conveniently modified to automate calculations for other credits under the Green-Star environmental rating system, and other environmental rating systems around the world. The study suggests that designers should consider the inverse relationship between building envelopes' total R-value with energy consumption and greenhouse-gas emissions. Another finding shows that materials used for building envelopes play a significant role to manage energy consumption as well as greenhouse-gas emissions amount during the building's life-cycle. [ABSTRACT FROM AUTHOR]

Buildings could be led to adverse impacts on environment, such as generation of construction and demolition waste, and emission of greenhouse gases (GHG). Therefore, promotion on development of green buildings is in need. With the increasing awareness in sustainable development, various rating tools are promoted to evaluate the performance of green buildings. Nowadays, these tools function as a guideline for green building development. There are various green building rating tools developed worldwide, and various countries follow different rules, incentives and regulations. However, despite of promotion of green building rating tools, environmental issues from buildings are still significant in Australia. This research compared green building rating tools in Australia and other countries or regions around the world. This research found that rating tools in Australia lack of (1) mandatory criteria and (2) regulations and incentives. This paper recommended that governmental incentives should be promoted. [ABSTRACT FROM AUTHOR]

Cement is one of the widely used materials in construction. Due to the adverse impacts towards the environment from cement manufacturing, green building rating tools always give a significant consideration towards concrete usage in green buildings. Irrespective of its significance in green buildings, there is a clear lack of research on life-cycle cost (LCC) impact of using supplementary cementitious materials (SCMs) in cement as required by green building rating tools. Therefore, this research analyses the life cycle costs of concrete using SCMs in obtaining concrete credits according to Green Star rating system in Australia. This research used fly ash, slag and silica fume as SCM for concrete. The SCM replacement percentage in concrete ranges from 10% to 60% as higher than 60% substitution is impractical. This research calculated LCC for each replacement percentage and specific building elements in different strength categories. LCC of concrete decreases with higher SCM replacement percentages. Further, there are only slight differences in LCC when comparing the three SCMs. In LCC, the contribution from the initial material cost is approximately 85%–87%, and in an exceptional situation such as in columns, this lowers to 66%. In larger columns, the cost of demolition is greater than that of the initial cost whereas it contributed to 61%–68% of the LCC. [ABSTRACT FROM AUTHOR]

The construction industry has a significant contribution towards numerous adverse environmental impacts. Therefore, green building concept has gained wide recognition. In line with this, numerous international green building rating tools have been developed providing a yardstick for measuring green building performance. These rating tools have different credit criteria for evaluating the green building performance. According to the existing literature, there are many researches comparing different green building rating tools on specific credit criteria such as “Energy”. However, there is a clear lack of research on establishing a baseline to develop new green building rating tools and to evaluate existing green building rating tools. Therefore, this research aims to establish key credit criteria based on an extensive literature study and evaluate these criteria based on widely used eight green building rating tools. The comparison analysis is based on a quantitative measure, namely, a normalised score, which is obtained through allocating credit points of selected green building rating tools to the established key credit criteria. The comparison result is presented with radar diagrams and bar charts. This research established seven key credit criteria for these rating tools which are namely (1) Site, (2) Energy, (3) Water, (4) Indoor Environment Quality (IEQ), (5) Material, (6) Waste and pollution, and (7) Management. It is found that ‘Energy’ criterion is the most widely considered key credit criteria and then followed by ‘IEQ’ and ‘Water’ criteria. Apart from that, credit criteria such as ‘Triple bottom line reporting’, ‘Education and awareness’, ‘Economic aspects relating to various costs’, ‘Sustainable designing and planning’ and ‘Stakeholder relations’ are identified as possible credit criteria which can be included in developing the rating tools in future. These key credit criteria can be adopted as a baseline to develop new green building rating tools, and it provides fruitful results to develop the existing tools further. [ABSTRACT FROM AUTHOR]

The concept of sustainability is regarded to be threefold: environmental, economic, and social. This is usually identified as the triple bottom line of sustainability and is often represented by three intertwined circles. Therefore, for a construction to be sustainable, it should be environmentally, economically, and socially sustainable. However, the extent to which green building rating tools evaluate the three pillars of sustainability is questionable. This research aims to analyze the effectiveness of eight international green building rating tools in evaluating environmental, economic, and social sustainability in buildings. The credit points of each rating tool was initially categorized based on the related category of sustainability and a comparison analysis was carried out based on a normalized score. Finally, the comparison result is presented with a radar diagram. Further, three case study buildings were also analyzed based on the credit points achieved. Accordingly, environmental sustainability is widely considered in green building rating tools while economic sustainability is rarely evaluated. Further, social sustainability is evaluated in all the green building rating tools, which would approximately amount to 20% of the credit points allocated by each rating tool. [ABSTRACT FROM AUTHOR]

Green buildings are gaining popularity in Australia with the applications of Green Star rating scheme. However, the credit for using timber materials in the rating scheme, while timber being a significantly used material in the fast growing residential construction industry, does not adequately guide designers and builders on the selection of the best timber types for residential applications from the life cycle perspective. This research presents the analysis on the life cycle cost of timber materials in their various applications for residential buildings in Australia and thereby provides guidance on how to best meet the requirement set out in the timber credit in the Green Start rating scheme. Structured interviews were used to collect the data on the cost of timber materials in their lifetime from builders, tradesmen and other residential construction professionals. Three sets of cost information were received under each application, for the individual timber species against three conditions (low, medium and extreme weather) with reference to residential buildings. Based on life cycle cost analysis results, the most suitable timbers for different applications are recommended. [ABSTRACT FROM AUTHOR]